Defrost indicator for frozen food packages



Jan. 9, 1968 c. F. KAYE 3,362,834

DEFROST INDICATOR FOR FROZEN FOOD PACKAGES Filed May 11. 1965 fimzimxmwg 3 Q A r g ,m

United States Patent 3,362,834 DEFRGST INDICATOR FOR FROZEN FOODPACKAGES Charles F. Kaye, 51 Edsell Road, Littleton, Mass. 01460 FiledMay 11, 1965, Ser. No. 454,927 3 Claims. (Cl. 99192) This inventionrelates to a defrost indicator for frozen food packages, and pertainsmore particularly to improvements in an indicating device adapted to beinserted through a Wall of a frozen food package and to display acolored signal in the event the contents of the package have becomedefrosted during transportation, storage, or when displayed in thecabinet of a food store or market.

I am aware that various types of defrost indicators have heretofore beendesigned for this purpose, but, so far as I am aware, none of them hasproved commercially successful.

It is accordingly the principal purpose of this invention to provide apractical and commercially usable, safe and eflicient defrost indicatorwhich may 'be easily applied to frozen food packages of various forms,which will display a clearly visible signal in the event the containedfoods become defrosted, whether or not the package is refrozen, andwhich will react to temperature elevation within the package rather thanto changes in temperature outside the package.

The novel features and advantages of the improved indicator will becomeapparent from the following description of the recommended embodiment ofthe invention shown on the accompanying drawings; but it will beunderstood that the structural details of the device herein illustratedand described may be varied to suit particular purposes or conditionswithout departing from the essence of the invention as set forth in theappended claims.

In the drawings,

FIG. 1 is a perspective view of a representative frozen food package towhich the improved defrost indicator has been applied;

FIG. 2 is a sectional view of the indicator in a first stage orcondition;

FIG. 3 is a view similar to FIG. 2 showing a second condition or stageof the indicator, prior to insertion into the food package;

FIG. 4 is another view similar to FIG. 3, showing a third stage of theindicator, as inserted into the frozen food package, prior to anydefrosting of the contents; and

FIG. 5 is a view similar to FIG. 4 showing a fourth condition or stageof the indicator after defrosting of the contents of the package hasoccurred.

In the embodiment chosen for the purpose of illustration, the defrostindicator comprises a tube 11 of Lucite or other non-toxic, plasticmaterial, preferably having an annular flange 12 at one end. In use, thetube 11 is inserted into a frozen package 13, through a suitable openingformed in a wall of the package, with the flange 12 disposed on thesurface of said wall and suitably secured thereon, adhesively orotherwise.

The tube 11 has an axial bore 14 of relatively small diameter, and endrecesses or chambers 15 and 16 of relatively large diameter. A diaphragm17, of rubber or odrer expandable and resilient material is located inthe bottom of chamber 15 and is preferably secured in place by a washeror grommet 18 which is adhesively attached to the wall of the chamberand which bears upon the 3,362,834 Patented Jan. 9, 1968 peripheralmargin of the diaphragm or resilient membrane 17 (FIG. 2).

In order to condition the indicator for its intended purpose, thediaphragm is firstdrawn outwardly to a bulblike position 17 (FIG. 3) bya vacuum or suction pump (not shown) suitably applied to the mouth ofchamber 15; the bulb 17 and the bore 14 of the tube 11 are then filledwith water 19 containing a non-toxic food coloring, such as red, fromthe open end of the tube at the chamber 16; and a pressure seal, such asthe plastic disc 20, is placed over the entrance of the bore at thebottom of the chamber 16, and secured in place by adhesive or otherwise.The colored liquid is preferably injected into the bore 14 while thetube 11 is supported with its bulb 17' downmost. The bulb should befilled with the liquid, but the bore need not be completely filled.After such sealing, the vacuum or suction appliance may then be detachedfrom the mouth of chamber 15.

The indicator is thus converted to its second stage or condition, asshown in FIG. 3, and may be inserted into the food package in thatcondition, or may be frozen before such insertion. In either event, theliquid in the bulb and bore is frozen solid, as at 19 in FIG. 4, so thatthe frozen liquid provides a source of restrained potential energy whichis released upon subsequent melting.

Next, either before or after the frozen indicator has been inserted intothe frozen food package, an opening 21 is pierced in the center of thesealing disc 20, and a second disc 22, of blotting paper or otherabsorbent material, of white or neutral color, is placed upon the disc29, Within chamber 16, and suitably secured thereto, over the opening21. Otherwise, the absorbent disc may be held in place by a larger disc23, of transparent plastic or the like, suitably applied to the outerend of the tube 11 and its flange 12 (FIG. 4). The indicator, in thisthird condition or stage, is ready for insertion into the frozen foodpackage 13, if not previously inserted, and to display a visible signal,if and when the contents of the package become defrosted.

In that event, the frozen colored water 19' in the tube bore and in theexpanded bulb 17 will melt, and the resilient diaphragm 17 will deflectto its initial position (FIG. 5), thereby helping to convey the water inthe bore through the opening 21 in sealing disc 20, to saturate theabsorbent disc 22 which will display the signal color red, or otherselected color, through the transparent cover disc 23.

The visible colored signal will indicate to the observer of the packagethat the contents of the package have been defrosted, and possiblyspoiled, even though the package should be refrozen. The absence of sucha color signal will ensure the prospective purchaser, and the shippersand store personnel, that the package has been maintained in frozencondition and is suitable for sale and consumption.

I claim:

1. A defrost indicator for insertion into frozen food packages,comprising a tube having a bore of relatively small diameter, and havingrecessed chambers of relatively large diameter at its opposite ends; aresilient diaphragm secured in the bottom of one of said chambers andexpanded into bulb form within said chamber; a frozen colored liquiddisposed in said bore and said expanded diaphragm ibulb; a sealing discsecured over the mouth of the bore in the other chamber; said sealingdisc having an aperture communicating with the bore, while the liquid isfrozen; and a liquid absorbent disc secured to the outer 3 surface ofthe sealing disc over its aperture, and adapted to absorb the coloredliquid when the liquid is melted and conveyed through said aperture uponthe deflection of the resilient diaphragm thereby indicating thatthawing of the frozen food to which the indicator is associated hasoccurred.

2. A defrost indicator as described in claim 1, said diaphragm beingsecured in said chamber by a washer fastened to the Wall of said chamberand bearing upon the peripheral margin of the diaphragm.

3. A defrost indicator as described in claim 1, said tube having anannular flange at the end adjacent to said disc-containing chamber, anda transparent cover disc applied to said end of the tube and to its saidflange.

References Cited UNITED STATES PATENTS 2,788,282 4/ 1957 Hammond 991922,951,764 9/1960 Chase 99192 3,055,759 9/1962 Busby et a1. 99192 10RAYMOND N. JONES, Primary Examiner.

S. DAVIS, Assistant Examiner.

1. A DEFROST INDICATOR FOR INSERTION INTO FROZEN FOOD PACKAGES,COMPRISING A TUBE HAVING A BORE OF RELATIVELY SMALL DIAMETER, AND HAVINGRECESSED CHAMBERS OF RELATIVELY LARGE DIAMETER AT ITS OPPOSITE ENDS; ARESILIENT DIAPHRAGM SECURED IN THE BOTTOM OF ONE OF SAID CHAMBERS ANDEXPANDED INTO BULB FORM WITHIN SAID CHAMBER; A FROZEN COLORED LIQUIDDISPOSED IN SAID BORE AND SAID EXPANDED DIAPHRAGM BULB; A SEALING DISCSECURED OVER THE MOUTH OF THE BORE IN THE OTHER CHAMBER; SAID SEALINGDISC HAVING AN APERTURE COMMUNICATING WITH THE BORE, WHILE THE LIQUID ISFROZEN; AND A LIQUID ABSORBENT DISC SECURED TO THE OUTER SURFACE OF THESEALING DISC OVER ITS APERTURE, AND ADAPTED TO ABSORB THE COLORED LIQUIDWHEN THE LIQUID IS MELTED AND CONVEYED THROUGH SAID APERTURE UPON THEDEFLECTION OF THE RESILIENT DIAPHRAGM THEREBY INDICATING THAT THAWING OFTHE FROZEN FOOD TO WHICH THE INDICATOR IS ASSOCIATED HAS OCCURRED.